


The New Equipment

by Nillas NSFW Corner (Agraulis_vanillae)



Category: Undertale (Video Game)
Genre: Alphyne, Alphys is Adorably Excited about Science, Alphys/Undyne-centric, Established Alphys/Undyne, F/F, Fluff and Smut, Grinding, Riding, Smut, Soul Sex, Undyne's Totally Gonna Tap That, Vaginal Fingering, Yuri
Language: English
Status: Completed
Published: 2016-07-20
Updated: 2016-07-20
Packaged: 2018-07-25 16:32:50
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,819
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7539871
Author URL: https://archiveofourown.org/users/Agraulis_vanillae/pseuds/Nillas%20NSFW%20Corner
Summary: <blockquote class="userstuff">
              <p>Undyne can't get over how cute and passionate Alphys is when she gets new science equipment.</p>
            </blockquote>





	The New Equipment

“AHHHHH Oh my gosh, oh my gosh, ohmygoshgoshgosh METTATON IT'S HEREEEE!!” Alphys's delighted squeals filled the air after a delivery truck dropped off a package and drove away. Mettaton's interest was low to moderate as she cut through the tape and twisted the cardboard packaging to reveal a compact microscope. He smiled indulgently anyways, happy to see the shy little lizard so excited about something that her stuttering fell away temporarily.

She was squealing softly to herself as she collected the different parts of the microscope, from the batteries and the tool to open the panel that would hold them, to the charger, the USB cord, and a couple of extra parts. “Metta, do you know what this is?!” She held up a cylindrical part gleefully, still somewhat wrapped which made it difficult for him to read the markings inside.

“What is it, dear Alphys?” he rolled across the room to peer over at it.

“This is a camera that goes ON the microscope, through the eyepiece! I plug the USB cord in here, and I can take pictures of microorganisms and keep them in my computer, maybe even post them online!” she babbled happily. “This is so AWESOME!!! This is way better than the old equipment Underground!”

Mettaton congratulated her politely, patently uninterested in such matters. Alphys continued, “I can't wait to show Undyne!” She squealed once more, all but hugging the new equipment before setting it up to test out it's capabilities. Eventually Mettaton left to attend the latest branches of his expanding MTT brand, allowing her to drool over the equipment in private.

~

Alphys was deeply focused on adjusting the microscope on different slides and taking pictures to organize and categorize on her computer, occasionally posting a photo of microorganisms that were dyed a particularly brilliant color or an unusual shape to the Undernet for her followers to see. Most of them weren't particularly interested, being more interested in anime or friends from discussion boards, but it did alert Undyne to what she was doing as she checked her social account before she visited.

Letting herself in, Undyne managed to make her way quietly through the apartment to see Alphys surrounded by her work, deftly manipulating the microscope to obtain the clearest picture, and occasionally cleaning the lens with that special tissue paper she uses to sop up excess mineral oil. Undyne spoke slyly, “So this is where you've been all day.”

Alphys jumped as she knew she would, and would've whirled around to face her if she hadn't draped her arms across her shoulders and firmly anchored her in place. She chirped happily, albeit a little flustered, “U-Undyne! The new microscope came today!”

“I noticed,” Undyne nuzzled the crook of her neck. “Keep doing what you're doing! I'll be just fine right here, thanks.”

They chatted amiably, with Alphys telling her all about the microscope's capabilities and the convenience of being able to check different slides through photo files instead of having to bring out the microscope all the time, and Undyne in turn telling her about running into humans that arrange different courses for their canines to practice agility training and making up a similar trial for Papyrus and the ex-guard canines. Obviously, there were a few modifications she made that was way more badass, complete with a table full of food that they were supposed to puke back up in a rhythm based puzzle.

Admittedly, she couldn't actually get Papyrus to take the course, the poor guy promptly turning tail as soon as the words 'puke puzzle' left her mouth.

Meanwhile, with Undyne's arms hanging over Alphys's shoulders, she began playing with her breasts, softly rubbing and petting as Alphys tried her hardest remain focused on what she was naming the latest file folder and not the sensation of Undyne's fingertips massaging through her shirt. 

“You're naming your second file folder after me, Alphie,” Undyne chuckled lowly, as she pressed her cheek to Alphys's cheek. “You really need to stay focused on what you're doing.”

Alphys jumped, turning a shade of red that contrasted with her pale sunny skin and she checked what was actually inside the folder so that she can rename it. The mouse stuttered across the screen as Undyne slipped a hand inside her shirt to gently trace around her areola and then flick across her hardening nipple. Undyne planted a kiss in the crook of her neck, pressing her lips languidly into the soft and sensitive skin as she readjusted her position to wrap her arms across Alphys's waist. All productivity shuddered to a halt, with Alphys slowly shutting down.

“Keep talking, I love it when you talk nerd like this,” Undyne encouraged huskily. “You're so passionate.”

“O-okay... w-well as I w-was saying- uh, oh...” Alphys tried to talk through the distraction and regain her train of thought only to be derailed again by Undyne's unoccupied hand following her hipbone inward and knead suggestively at the skin just below the curve of her stomach. Well aware of where this was going, Alphys barely remembers to remain on task and carefully removes the glass slide from the microscope and into its case. “I-I was just saying that this i-is already such a huge d-difference from the old microscope I had in the o-old lab-”

She gulps, her breath hitching audibly as Undyne casually flicks at her nipple and slips a hand below her pajama pant's waistband and presses a couple of fingers into her slit. “I'll bet you'll really put that 'scope to work, huh?” Undyne purred.

“P-probably,” Alphys agreed breathily, unable to keep a note of anticipation out of her voice.

“C'mon Alphie, tell me how much work you're gonna put that microscope through,” her girlfriend prompted. She 'v's her fingers to open up the folds of Alphys's cunt and then slips her fingers close down to be coated by her collected arousal. There was nothing more Undyne liked than to listen to Alphys try to talk because even when she wasn't actively moaning or whimpering, her breath would catch in her throat as her body pressed back into the attention and the way her voice would tremble was honestly too cute.

“I'll p-probably need t-to use it e-every d-day for work ah, ahhhnnn...” Alphys's eyes fluttered shut and her glasses tipped forward precariously. Undyne paused from massaging her breast to pluck them off her face and set them safely aside. Crushing one pair of glasses while trying to get Alphys off once was enough, thank you. She resumed her attention by cupping Alphys's other breast, lifting her shirt just above her chest and burying her face even further into her shoulder. “... ahhhnd, as we a-adjust to the sss-surfaccce we'll n-need to record a-any changes in m-monster's h-health.”

Undyne bit her shoulder gently as she twisted her fingertips and curled them firmly into Alphys, earning the sweetest little squeak. She pressed her tongue to the bite and breathed, “You're so amazing and compassionate, how did I get so lucky with you as a girlfriend?”

Alphys tried to work her way out of her pleasurable haze to tell Undyne that she was really amazing, to protest her own comparable worth, but almost as if she read her mind Undyne pushed her digits further into her pussy and she shuddered in place in surprise. They slid further up against her walls. “Unnn... Undyne, you're killing me...” she moaned.

Undyne grinned against her neck, and she knew there wasn't going to much mercy from this go around. “God, you're so soft. Have you felt this?” She squeezed Alphys's boob, tweaking her thumb over her nipple yet again. “So voluptuous and sexy... I bet you could give some of these human sex symbols a run for their money.”

She carefully slides her hand out of Alphys, feeling her clench on her fingers before she slips out. Undyne gives an appreciative hum before pulling Alphys's shirt over her head and spinning the office chair in place so that she could kneel in her lap and look her in the eyes as she fingered her.

“Betty Paige doesn't light a candle to you babe,” she tells her, holding her face so to prompt her to open her eyes. She gave an experimental thrust with her fingers and Alphys trembled, eyes swimmingly wetly from the stimulation and the intensity with which she pressed her praises.

“Never mind Marilyn Monroe or any of the others, you are-” an added third finger, and the steady pistoning motion that struck up towards her cervix, precise and unyielding. Alphys was rocking her hips in response to the rhythm, panting and murmuring incoherently. She carefully slid her pants down with each shift in balance, exposing her pale thighs and knees.”-the smartest, sexiest, sweetest person I've ever known and it is so hot how passionate you are about your work these days.” 

Without breaking from the established rhythm, Undyne pushed a leg up to open her up so that she could kneel down and press her tongue firmly to her clit under her panties, flicking. Alphys's legs shook around her as she squeaked and clutched the armrest for dear life. Undyne curled her fingers inwards and dragged the pads of her fingertips down back to her opening for a change of pace. Alphys moaned aloud. With this new motion established, Undyne continued to work her up until Alphy's entire body was flushed and quivering, her breasts heaving with each tremulous breath.

She could feel her walls clenching with a steady pulse, that telling sign that the internal coil was about to snap free and pulled up the mons veneris to allow her to suck heartily at her clit. 

“Haaaah! Huh! Uhhhndyne!!!” Alphys cried and Undyne kept a steady pace even through the gush of cum that dripped into her palm and into her panties and pajamas.

“Good god, so wet,” Undyne moaned as Alphys's fluttering slowed to a stop and pulled her fingers out. She grinned roguishly at her girlfriend's heavy lidded gaze, and licked up the cum that coated her hand before gently lifting her by the hips and drinking up the rest straight from the source.

“P-please, n-no more...” Alphys whimpered, the muscles in her thighs jumping with over stimulation. “You've already b-blown my mind once t-today!”

“Can't help it, there's so much to clean up,” Undyne sighed dreamily. If Alphys could flush more, she would've but her skin was already a deep strawberry glow from seeing Undyne situated between her thighs with her face glistening in the light. “You squirted today.”

“C-couldn't help it,” Alphys mumbled abashedly. She wrapped her little hands around Undyne's face, palms pressed into her cheeks and thumbs brushing her angular cheekbones to give her a deep languid kiss. She tasted and smelt herself on Undyne, a part of her still stuck in a state of disbelief that this could possibly be a part of her life now. 

“Do you maybe have another round in ya?” Undyne said once they broke the kiss for air, hands already traveling up her thighs to maybe start tugging down her white cotton panties.

“W-w-wait! What about you?” Alphys squeaked, swatting her hands away in a panic. Undyne ground herself down on her heels from her kneeling position and then looked up, confident and lascivious.

“I bet I can get us both off at the same time!” 

Alphys knew that glint in her eyes, and sweated nervously. “B-but I want to h-help-”

Undyne lifted Alphys up by the butt to wrap her legs around her waist and carry her into her bedroom, “You'll be a huge help just by making more-”

She pressed her mouth hungrily to Alphys to swipe her tongue across Alphys's lips and suckling her lower lip until it was soft and swollen from stimulation and Alphys was gasping again. “- of those GORGEOUS goddamn noises!”

She threw Alphys on the bed, taking only the briefest of moments admire the way her breasts bounced with her before climbing back on top and kissing her heavily again. This time Alphys managed to instigate the deepening of the kiss and slid her tongue against hers, leaving Undyne to be lost in the slick hot daze. Alphys pressed her hands against her muscular stomach, admiring the sleekness of her form and the easy strength of her abdominal muscles before Undyne sat up with a gasp. Alphys looked at her with surprise, questioning what she might've just done before Undyne declared,

“I have an idea!”

Alphys pushed herself upright, “W-what is it? I-is it sixty-nine, 'cuz I-I was thinking-”

“Nuh uh! If I'm right about this, it could be even better,” Undyne pushed her back down and rubbed at Alphys's swollen clit as she summoned her lime colored soul. Alphys gazed at it with some awe before realizing that she should do something but Undyne held her down and straddled her. “You said you wanted to help, right? I want you to rock with me.”

She took her soul, gently pulsating and set it where it was trapped against Alphys's underwear and her vagina for her to mount and rub against. Undyne's face took on a particularly dark flush, her own eye closing in response to the waves of pleasure. “Mm, yeah... just like that Alphie...”

She leaned over for another open mouthed kiss as she shimmied her jeans off and thrust her hips up against Alphys, situating her thighs to straddle across her hips and putting her weight on her knees. They ground together heavily, Undyne losing herself to the intense electrifying feeling that radiated from her groin. Alphys recognized that she was soon going to break from the soul weeping magic and slowly vaulted so that Undyne was the one pressed against the sheets.

“I-I'd like to try something too,” she told her as she took control.

She slipped her panties off and spread her legs wider. Carefully rearranging the position of the soul, she thrust it deep inside her. Undyne's thighs pressed together and she pressed her heels down into the bed in a convulsive hip movement that nearly knocked Alphys forward. She caught herself just above Undyne, and found that this time Undyne was the one nearly in tears. Her red hair-like fin, was folded across her eye patch and glimmered beautifully. The soft yielding soul inside her was pulsing and emitting so much heat and fluid, she never felt so flooded quite like this. There was only a few moments left before both of them were over the edge.

“Please, I want you to make me c-cum while I eat you out,” she murmured. She shifted so that her hips were in easy range and forcefully spread Undyne's powerful thighs apart before she buried her tongue deep inside her. Undyne's lower half was pulled too far upward for her to kiss her pussy as well, but she pushed a couple of fingers in to to caress her quivering walls as her thumb rubbed messy circles into her clit. True enough, Alphys squealed as her orgasm hit, her walls locking around Undyne's soul and clenching it in a wash of milky fluid. Undyne screamed from the electrifying pleasure, incoherent as her hips snapped forward into Alphys's face.

The combined orgasm left Alphys dripping copiously on Undyne's chest, the soul having released a full amount of magic that flooded up far into her like a tidal wave and then drained in a steady stream. It slipped out to disassociate and Alphys released Undyne's thighs to flop over bonelessly, more than a little wobbily. For a few minutes, all that could be heard was heavy breathing as they basked in the afterglow.

“... should've known you'd find a way to make that better than even what I thought up,” Undyne grinned as she rolled over to cuddle her. “By the way, I'll have to add this to the looong list of reasons why you're the best thing in my life.”

She dipped her hands in the combined fluids that'd dripped onto her tank and held up the still slippery substance, and Alphys groaned with embarrassment, “O-oh my god Undyne... we need showers so bad right now.”

Undyne huffed with amusement, “As if! Can you walk right now? 'cuz I sure as hell can't. Let's worry about that after a nap.”

“Ewww!” Alphys squirmed as Undyne threw an arm over her. “Are you r-really gonna..?”

Undyne answered her with a fake snore, holding her close with an iron grip and Alphys sighed. “F-fine! B-by the way... I've got an even longer list. W-why you're the best thing in my life I mean!”

“Literally impossible,” Undyne muttered.

“Y-you wanna bet?!” Alphys demanded. She looked all riled up, ready to throw down, and Undyne felt a twinge in her groin return.

“You better watch out,” she growled, “Keep talking like that and we'll see if we even get the chance to shower.”

**Author's Note:**

> The first explicit work I write in years and it's yuri... somehow I have no problem with this! In any case, this is Agraulis vanillae and welcome to my NSFW corner! ;)


End file.
